Nephrolithiasis and bone involvement in primary hyperparathyroidism

PURPOSE: The purpose of this study was to compare patients with primary hyperparathyroidism with and without nephrolithiasis with regard to (1) biochemical profile, and (2) presence and extent of bone involvement. PATIENTS AND METHODS: Of 70 unselected patients enrolled in a longitudinal study on the natural history of primary hyperparathyroidism, 62 who underwent complete bone densitometry evaluation were considered. The patients had mild hypercalcemia (2.77 +/- 0.02 mmol/L), as well as elevated parathyroid hormone levels by mid-molecule, N-terminal, and immunoradiometric assays. Bone densitometry was assessed by dual-photon absorptiometry of the lumbar spine and femoral neck, and single-photon absorptiometry of the forearm. RESULTS: Eleven of the 62 patients (18%) had nephrolithiasis. There was no difference in serum parathyroid hormone levels, calcium, phosphorus, serum 25-hydroxyvitamin D, and 1,25-dihydroxyvitamin D3 between those with and without kidney stones. Total daily urinary calcium excretion was higher among those who formed stones (8.2 +/- 1.0 mmol versus 6.1 +/- 0.4 mmol, p less than 0.05), but not when expressed per mmol of creatinine (0.72 +/- 0.07 versus 0.69 +/- 0.04). Urinary hydroxyproline was also higher in patients who formed stones (58 +/- 11 mg/24 hours versus 37 +/- 2 mg/24 hours; p less than 0.05). Hypercalciuria occurred in 39% of the entire cohort (n = 24), and in 33% (n = 17) of those without stones. Only 29% (n = 7) of those with hypercalciuria had nephrolithiasis. Calcium excretion correlated positively with serum 1,25-dihydroxyvitamin D3 (r = +0.32, p less than 0.05), and negatively with forearm bone mineral density (all patients: r = -0.34, p less than 0.05; hypercalciuric patients: r = -0.53, p less than 0.05). Circulating 1,25-dihydroxyvitamin D3 levels were elevated in a similar proportion of (1) all patients (31%, n = 19); (2) those with nephrolithiasis (27%); and (3) those without stones (31%). Bone mineral density was less than 80% of normal in 61% of patients, but forearm, femoral neck, and lumbar spine density were indistinguishable among those with and without stones. CONCLUSIONS: Cortical bone demineralization occurs to the same extent and frequency in patients with and without nephrolithiasis, and these two subgroups share similar biochemical and bone densitometric profiles. The pathophysiologic events leading to renal and skeletal involvement in primary hyperparathyroidism may be less selective than previously believed, as evidenced by: (1) increased urinary hydroxyproline in patients with nephrolithiasis, and (2) documentation that urinary calcium excretion reflects not only vitamin D status, but bone resorption was well.     

Glutamine synthetase of Mycobacterium tuberculosis: extracellular release and characterization of its enzymatic activity.

We have investigated the activity and extracellular release of glutamine synthetase [L-glutamate:ammonia ligase (ADP-forming), EC 6.3.1.2] of Mycobacterium tuberculosis. The purified, homogeneous M. tuberculosis glutamine synthetase appears to consist of 12 most likely identical subunits of M(r) 58,000, arranged in two superimpose hexagons. In the catalysis of L-glutamine, the enzyme has an apparent Km for L-glutamate of approximately 3 mM at the pH optimum of 7.5. M. tuberculosis releases a large proportion (approximately 30%) of its total measurable enzyme activity into the culture medium, a feature that is highly specific for pathogenic mycobacteria. Immunogold electron microscopy revealed that M. tuberculosis also releases the enzyme into its phagosome in infected human monocytes. Two potentially important roles for glutamine synthase in the pathogenesis of M. tuberculosis infection are (i) the synthesis of L-glutamine, a major component of the cell wall of pathogenic but not nonpathogenic mycobacteria, and (ii) the modulation of the ammonia level in the M. tuberculosis phagosome, which may in turn influence phagosomal pH and phagosomelysosome fusion.     

Robotic-assisted total mesorectal excision (TME) for rectal cancer results in a significantly higher quality of TME specimen compared to the laparoscopic approach—report of a single-center experience

Aim

Robotic surgery allows for a better visualization and more precise dissection especially in the narrow male pelvis and mid and lower third of the rectum. However, superiority to laparoscopic TME has yet to be proven. We therefore analyzed short-term outcomes of laparoscopic and robotic low anterior rectal resection for rectal cancer.

Patients and methods

From 2011 to 2016, 44 robotic (RTME) and 41 laparoscopic (LTME) low anterior rectal resection with total mesorectal excision were performed at a single institution. Specimen quality was assessed and reported by an independent pathologist following international guidelines.

Results

The groups did not differ significantly regarding gender, age, ASA stage, BMI, and distance of the lower tumor margin from the anal verge. More patients in the RTME group underwent preoperative chemoradiation (43.2 vs. 19.5%, p?=?0.019). The quality of the TME specimen was significantly better in the RTME group (complete/nearly complete/incomplete for RTME 97/0/3% and for LTME 78/17/5%, p?=?0.03). The conversion rate tended to be lower in the RTME group (7 vs. 17%, p?=?0.143). There was no difference in CRM positivity between the groups.

Conclusion

Robotic surgery is safe and can improve the quality of TME for rectal cancer compared to laparoscopy. Any effect on long-term survival remains to be established.

     

Fluvastatin reduces the 4-year cardiac risk in patients with multivessel disease

BACKGROUND: To evaluate the impact of the extent of coronary disease (single- or multivessel) and of fluvastatin treatment on the incidence of long-term cardiac atherosclerotic complications in the Lescol Intervention Prevention Study (LIPS). METHODS: A total of 1063 patients with single-vessel disease and 614 patients with multivessel disease were randomized to receive fluvastatin (40 mg bid) or placebo for at least 3 years following a first successful percutaneous coronary intervention. The incidence of cardiac atherosclerotic events (cardiac death, non-fatal myocardial infarction, and coronary re-interventions not related to restenosis) was evaluated. RESULTS: Patients with multivessel disease tended to be older and presented a higher prevalence of associated risk factors and cardiovascular antecedents. The presence of multivessel disease markedly increased the risk of cardiac atherosclerotic events compared with single-vessel disease among patients allocated to placebo (RR 1.67 [95% CI: 1.24-2.25]; p<0.001). In patients treated with fluvastatin, however, no significant differences in long-term outcomes were observed between patients with multivessel disease and patients single-vessel disease (RR 1.28 [95% CI: 0.90-1.81]; p=0.2). CONCLUSIONS: Multivessel coronary disease impaired the 4-year outcomes after percutaneous intervention. However, the hazardous effect of multivessel disease was significantly reduced by long-term fluvastatin treatment.     

Principles and requirements for stroke recovery science

The disappointing results in bench-to-bedside translation of neuroprotective strategies caused a certain shift in stroke research towards enhancing the endogenous recovery potential of the brain. One reason for this focus on recovery is the much wider time window for therapeutic interventions which is open for at least several months. Since recently two large clinical studies using d-amphetamine or fluoxetine, respectively, to enhance post-stroke neurological outcome failed again it is a good time for a critical reflection on principles and requirements for stroke recovery science. In principal, stroke recovery science deals with all events from the molecular up to the functional and behavioral level occurring after brain ischemia eventually ending up with any measurable improvement of various clinical parameters. A detailed knowledge of the spontaneously occurring post-ischemic regeneration processes is the indispensable prerequisite for any therapeutic approaches aiming to modify these responses to enhance post-stroke recovery. This review will briefly illuminate the molecular mechanisms of post-ischemic regeneration and the principle possibilities to foster post-stroke recovery. In this context, recent translational approaches are analyzed. Finally, the principal and specific requirements and pitfalls in stroke recovery research as well as potential explanations for translational failures will be discussed.     

Extended stereotactic brain biopsy in suspected primary central nervous system angiitis: good diagnostic accuracy and high safety

Journal of Neurology - To evaluate the diagnostic accuracy and safety of extended stereotactic brain biopsy (ESBB) in a single center cohort with suspected primary angiitis of the central nervous...     

Magnetic Polymer/Nickel Hybrid Nanoparticles Via Miniemulsion Polymerization

This work shows a method to synthesize and encapsulate magnetic nickel nanocrystals into polymeric colloidal particles through miniemulsion polymerization. The nickel nanoparticles are produced by a thermal decomposition method in the presence of oleylamine and triphenylphosphine, which results in a hydrophobic surface. However, being compatible with the monomer does not ensure a successful encapsulation by miniemulsion polymerization, as the nickel nanoparticles are expelled from the polymer particles with increasing styrene conversion due to the poor adhesion interaction between the organic shells of the nickel nanoparticles and the polystyrene. Changing the hydrophobic polystyrene to a polymer with higher polarity such as poly(methyl methacrylate) proves to be efficient for encapsulation of nickel nanoparticles when employing a hydrophilic initiator. After encapsulation, these nanoparticles show magnetic response.

     

A retrospective analysis of autotransplanted teeth including an evaluation of a novel surgical technique

Clinical Oral Investigations - To assess survival rates and frequency of complications for immature and mature autotransplanted teeth after at least 1 year in function. All consecutive patients who...